Detection and communication of plunger position using induction

Abstract

A syringe system, including a plunger, a microcontroller, a battery, and a coil. The syringe barrel having a proximal end, a distal end, and a cylindrical sidewall defining a longitudinal axis, the cylindrical sidewall extending longitudinally between the proximal and distal ends, the sidewall having an exterior surface and defining an internal volume, the plunger being positioned between the proximal and distal ends of the syringe barrel and being movable within the internal volume with respect to the syringe barrel in the longitudinal direction. The syringe barrel further includes a label disposed on the sidewall and having at least two conductive strips extending in a non-parallel direction with respect to the longitudinal axis and having unique lengths. The microcontroller is configured to determine a position of the plunger with respect to the syringe barrel by measuring a current induced in the coil by the at least two conductive strips.

What is claimed is: 
     
       1. A syringe system, comprising:
 a plunger including:
 a microcontroller, 
 a battery, and 
 a coil connected to the microcontroller and the battery by two or more electrical leads; and 
 
 a syringe barrel having a proximal end, a distal end, and a cylindrical sidewall defining a longitudinal axis, the cylindrical sidewall extending longitudinally between the proximal and distal ends, the sidewall having an exterior surface and defining an internal volume, the plunger being positioned between the proximal and distal ends of the syringe barrel and being movable within the internal volume with respect to the syringe barrel in the longitudinal direction, the syringe barrel further including:
 a label disposed on the sidewall having at least two conductive strips extending in a non-parallel direction with respect to the longitudinal axis having unique lengths; 
 
 wherein the microcontroller is configured to determine a position of the plunger with respect to the syringe barrel by measuring a current induced in the coil by the at least two conductive strips. 
 
     
     
       2. The system of  claim 1 , wherein the plunger includes a head section, at least a portion of which extends outside of the syringe barrel, and the battery and the microcontroller are disposed in the head section. 
     
     
       3. The system of  claim 1 , further including a temperature sensor configured to output a signal representative of a temperature of the syringe system to the microcontroller. 
     
     
       4. The system of  claim 3 , further including a wireless communication interface, the microcontroller being configured to transmit the temperature data received from the temperature sensor to a smart device via the wireless communication interface. 
     
     
       5. The system as recited in  claim 1 , further including a wireless communication interface, the microcontroller being configured to transmit plunger position data to an external device via the wireless communication interface. 
     
     
       6. The system as recited in  claim 5 , wherein the external device is configured to provide an alert to a user if the plunger position is determined by the microcontroller to have moved in excess of a predetermined distance. 
     
     
       7. The system as recited in  claim 1 , wherein the microcontroller is configured to periodically cause the battery to supply current to the coil at predetermined intervals. 
     
     
       8. The system as recited in  claim 1 , wherein the at least two conductive strips are transparent. 
     
     
       9. The system as recited in  claim 1 , wherein the at least two of the conductive strips are arranged on the sidewall of the barrel so as to be spaced apart from one another in the longitudinal direction, and are arranged in order according to circumferential length. 
     
     
       10. A method of using a syringe system including a plunger having a microcontroller, a battery, and a coil connected to the microcontroller and battery by two or more electrical leads, a syringe barrel defining a longitudinal axis and receiving the plunger, and a label disposed on a sidewall of the syringe barrel and having at least two conductive strips extending in a non-parallel direction with respect to the longitudinal axis and having unique lengths, the method comprising:
 generating, by the microcontroller, an eddy current in the coil by causing the battery to supply a current to the coil via the two or more electrical leads, whereby an amplitude of the generated eddy current depends on a relative position of the coil with respect to the at least two conductive strips of the label along a longitudinal direction of the syringe barrel; 
 measuring, by the microcontroller, the generated eddy current in the coil via the two or more electrical leads; and 
 determining, by the microcontroller based on the measured eddy current, a position of the plunger with respect to the syringe barrel. 
 
     
     
       11. The method of  claim 10 , further comprising:
 transmitting, by the microcontroller via a wireless communication interface, data regarding the determined plunger position to an external device. 
 
     
     
       12. The method of  claim 11 , further comprising:
 generating, by the external device, one or more alerts based on data regarding the plunger position. 
 
     
     
       13. The method of  claim 10 , further comprising:
 generating, by a temperature sensor, temperature data based on a measured temperature of the syringe system; and 
 transmitting, by the microcontroller via a wireless communication interface, the temperature data to an external device. 
 
     
     
       14. The method of  claim 13 , further comprising:
 generating, by the external device, one or more alerts based on the temperature data.